Power-transmission device



LMSM.

L. LEE

POWER TRANSMISSION DEVICE.

FILED AUG 3o 1920 Jan 23, 1923.

lli

llllll LEJEF LEE, Ol? YOUNGSTOWN, OHIO.

POWER-TRANSMISSIIN JDVICIE.

application filed August 30, wat). Serial' ltlo. toegaat.

To all -wlzom t may concern.'

Be it known that l," Lair Lien, a citizen of the lUnited States, residing at Youngstown, Mahoning County, hio, have invented a new anduseful Improvement in Power-Transmission Devices, of which the following is a full, clear, and exact description.

'll`he 'present invention relates broadly to power transmission devices, and more particularly to vdevices of this nature adapted to slip when the load is increased beyond a predetermined maximum.

llt has heretofore been proposed to'v construct power transmission devices adapted to fri'ctionally transmit power, and comprising driving and driven members having frictional interengaging means. 'llhe present invention relates to a construction of this general nature, and provides an easily adjustable means for regulating the point of slip, and controlling springs of maximum length and efficiency. 'llheentire construction is such that the operating parts may run in an oil bath thereby greatly increasing the life of the device.

The foregoing and other objects, together with their attendant advantages, will be apparent as the invention becomesbette'r understood, by reference to the accompanying' specification and drawings forming a part thereof, it being premisedthat changes may j be made in the various details and the manner of operation, within the Scope ofthe appended claims, without departing from the spirit of the invention.

- Figure 1 is a partial sectional view'on theline ll-l of Figure 2, the housing being omitted, and 1 Figure 2l is a sectional view illustratingr one method of assembling the driving and driven members.

Referring more particularly to the drawings, there is illustrated a power transmis sion device comprising a driving shaft 2 having a worm 3 thereon in engagement with a worm wheel d. lin the present embodiment, the worm wheel is illustrated as comprising a ring gear suitably secured to a hub 5 freely rotatable on the driven shaft 6 within a conventional housing 7 of anv usual construction. j

Also secured to the hub 5 is an annular Hanged member 8, constituting a driver, and provided with a series of equally spaced curved grooves 9 in the inner face thereof,

the number and construct-ion of 'which may be varied as desired. Adapted to engage diametrically opposite grooves 9 are rollers 1() rotatably carried by the ends of levers 11 having fulcrums 12 on a hub 13 which is splined to the driven shaft 6. rlhe oppositeends of each of the levers 11 have secured thereto tension rods 141 having their free ends threaded to adjustably support follower heads 15 engaging compression springs 16 suitably mounted in pockets or cylinders 17 formed in the hub 13. By adjusting the position of the heads 15 longitudinally of the tension rods 14: by means of the nuts provided, it will be apparent that the frictional` engagement between the rollers 1() and the inner face of the flanged member 8 having the radiused grooves 9 may be increased or decreased as desired. Withthe springs 16 slightly compressed, a comparatively light load on the shaft 6 may be sufficient to cause the rollers 10 to ride out of the groovesl 9 against the force exerted by the springs. This will result in slipping between the driving and driven members, the slipping continuing until the load is decreased sufliciently to permit re-engagement of the rollers with the nearest grooves 9. By increasing the compression of the spring 16, the Vopposition to slipping will be increased proportionately, thereby enabling the transmission of any desired torque below a predetermined maximum. i

lf desired, the entire housing 7 may be lilled with oil to insure ease of operation of the slip gear. rll`loe provision of the rollers 10 decreases friction during the periods of slipping whereby the maintenance cost is decreased and the length of life of the device increased. llue to the location of the grooves 9, it will be obvious'that driving engagement will be automatically re-established substantially simultaneously with the decrease in the load, while the opposed points ot engagement balance the: force exerted by the respective springs. I

llt will be apparent that the present invention is adaptable for use in any construction requiring a Hexible coupling between relatively movable members, and the term power transmission device as used throughout the specication and claims is to be construed broadly enough to be definitive of such a use. j

v'lhe advantages of the present invention arise from the provision of a power transmission device adapted to slip under conditions which may be changed 'easily as required.

I claim:

l. A power transmission device, comprising a rotary member having a series of grooves formed therein, a second rotary member having a pocket formed therein, a lever pivotally carried by said second member, a roller on one end of said lever adapted to cooperate with said grooves, a spring in said pocket and means cooperatively connecting said spring and the opposite end of said lever to exert a yielding pressure on said roller, substantially as described.

2. In a power transmitting device? a driving member, a driven member, one of said members having a pivotally mounted lever with la roller carried by one id thereof, the other of said members having an irregular bearing surface adapted tobe'engaged by said roller, a tension rod secured to the opposite end .of said lever, and a compression spring surrounding said rod for holding the roller in engagement with saidY bearing surface, substantially as described.

3. In a power transmit-ting device, a driving member, a driven member, one of said members having a pivotally mounted lever vwith a roller carried by one end thereof, the

other of said members having an irregular bearing surface adapted to be engaged by said roller, a tension rod secured to the opposite` end of said lever, a compression spring surrounding said rod for holding the roller in engagement with said bearing surface, and means on said tension rod for varying the force exerted by said spring, substantially as described.

4. In a power transmissio-n device, a flanged rot-ary member having a. series of grooves formed in the inner surface of the flange, a second rotary member, at least a part of which lies within said ange, a plurality of levers pivotally mounted on said second member, a roller carried by one end of each of said levers for engagement with said grooves, a tension rod secured to the opposite end of each of said levers, and compression springs surrounding said rods for maintaining the 'rollers in engagement with said grooves, substantially as described.

5. In a power transmission device, a 4flanged rotary member having a series of grooves formed in the inner surface of the flange, a second rotary member, at least a part of which lies within said flange, a plu- Arality of levers pivotally mounted on said second member, a roller carried by one end of each of said levers for engagement with said grooves, a tension rod secured to the opposite end of each of said levers, compres sion springs surrounding said rods for maintaining the rollers in engagement with said grooves, and means on said rods for varying the force exerted by said springs, substantially as described.

6. In a power transmission device, a rotary member having a series of grooves formed therein, a second rotary member, a plurality of levers pivotally mounted on diametrically opposite sides of said second member, a roller carried by one end of each of said levers for engagement with saidl grooves, and springs extending across the axis of rotation of said second member and cooperating with the opposite ends of said levers for maintaining the rollers in engagement with t-he grooves, substantially as described.

A7. In a power transmission device, a rotary member having a series of grooves formed therein, a. second member having a, plurality of oppositely extending pockets formed therein, a plurality of levers pivot- "ally carried by'said second member, a roller on one end ofweach of said levers adapted to cooperate with said grooves, tension rods secured to said levers and extending into said pockets, and springs in said pockets and surrounding said rods fer exerting a yielding pressure on the rollers, substantially as described.

8. In a power transmission device, a rotary member having a series of grooves formed therein, a second member having u plurality of oppositely extending pockets formed therein, a plurality of levers pivotally carried by said second member, a roller on one end of each of said levers adapted to cooperate with said grooves, tension rods secured to said levers and extending into said pockets, sp-rings in said pockets and surrounding said rods for exerting a yielding pressure on the rollers, and an oil receiving casing operatively enclosing said members, substantially as described.

` In testimony whereof, I have hereunto set my hand.

LEM" LEE. 

